Relationship between extreme precipitation and dry spell and particulate matter concentration in the metropolitan region of Sao Paulo

Abstract

The present work aims to identify and quantify the relationship between extreme precipitation and dry spell events and particulate matter concentration in the Metropolitan Region of São Paulo by analyzing meteorological and precipitation data. Days, when the accumulated precipitation volume is greater than 95% and represents a 5% frequency of occurrence, are considered extreme precipitation days. A dry spell is a prolonged period with precipitation rates below the average or null. Particulate matter concentration before and after the extreme precipitation events and during dry spells will be evaluated from 2011 and 2020. A decrease in the number of days with precipitation, particularly during the rainy seasons, may cause an air quality worsening in the region that will in consequence bring harmful effects to human health, as well as to the whole local biodiversity. The data collection and analysis will allow the verification of whether particulate matter concentrations remain within the limits established in the State Decree nº 59113 23/04/2013, how many exceedances of the limit happened in this ten years, and the influence of the extreme precipitation and dry spell events on air quality. This information may be used by the public power to prevent bad air quality episodes, controlling emissions, for instance. (AU)